Italian reformer, b. Ravenna. He became a Camaldolese monk at Fonte-Avellino
(near Gubbio) and because of his rigor and asceticism was made prior. He
was a strong advocate of church reform and wrote (c.1050) the Liber
Gomorrhianus, a scathing denunciation of clerical immorality and homosexuality
that created a sensation. In 1057 Stephen IX made him a cardinal against
his will. Nicholas II sent him as legate to Milan, notorious for simony
and clerical concubinage. In 1069 Alexander II sent him as legate to settle
the quarrel between Roman Emperor Henry IV and the empress. In the dispute
with Berengar of Tours Peter deprecated the application of reason in theology.